Oscillating mechanism for washing machines and the like



O. J. VOSS April 14, 1953 OSCILLATING MECHANISM FOR WASHING MACHINES AND THE LIKE Filed Aug. 15. 1949 2 SHEETS-SHEET 1 Fl a. 35 12 Z5 /7 G INVENTORI OTTO J. Voss ATTORNEYS.

FIG I].

April 14, 1953 o. J. voss 2,634,615

OSCILLATING MECHANISM FOR WASHING MACHINES AND THE LIKE Filed Aug. 15, 1949 2 SHEETS-SHEET 2 FIG. 2.

(can @xagggiifisgq! fi INVENTOR'.

OTTO J. voss 24 M a g r:

FIG. 6- Byfillklt,

ATTORNEYS.

Patented Apr. 14, 1953 UNITED "STATES ATEENT OFFICE -OSCILLATI'NG vlt IEGHANISM FOR WASHING -MACHINES AND THE-LIKE 7" Claims. 1

This invention relates generally to washing machines and particularly to an oscillating mechanism therefor.

' In the usual washing machine, an agitator is provided within a tub and adapted to be oscillated therein about a vertical axis. The source of motive power for the agitator and other moving parts of the machine is an electric motor or gasoline engine, which delivers its power as unidirectional (when the agitator is being driven) rotation. Since it is not feasible to'reverse the direction'of the'motive power upon each half cycle of'agitator oscillation, various 'mechanisms have heretofore been provided for converting the'rotary motion of the source of motive power into the oscillatory rotation of the agitator. For brevity, the mechanisms for converting unidirectional rotary motion into oscillatory rotary motion are herein referred to as oscillating mechanisms. The oscillating mechanisms heretofore provided in washing machines have constituted a source of annoyance, not only to the manufacturer, but to the user, of themachine. The repeated reversal of direction to which the parts are subjected, particularly when under load, results in a constant hammering of the parts together, with consequent wear, loosening, and development of noise.

In the patent'toKuhlmann, No. 1,696,718, it was proposed to utilize an adaptation of the familiarfilndian fire stick principle as the oscillating mechanism of a washing machine,' but in the adaptation there disclosed, the device was productive of considerable noise and slap, even when new and properly adjusted, and the magnitude of the noise and slap increased as the parts wore in. Consequently, this type of oscillating mechanism met with no favor in the art.

The object of the invention, generally stated, is to provide a noiseless oscillating mechanism for a washing machine, and one which is not subject to the development of noiseduring normal use.

Another object of the invention is to providean oscillating mechanism for a washing machine wherein the parts require no adjustment during use, or' because of use.

Other objects will become apparent to those skilled in the art when the following description is read in connection with the accompanying drawings, in which:

figure 1 is a view in sideelevation of a washing machine embodying the oscillating mechanism of the present invention, part beingbroken awayv to reveal the relation. of the several parts of the machine;

Figure 2 is an enlarged view of'the oscillating mechanism, taken in the same elevation astthat of Figure l,wi.th .part o'f'the casebrokenaway'to reveal the internal partsiof the'oscillating'mecha-' nism;

Figure 3 is a sectional view taken along line-3 3 of Figure 2;

Figure 4 is a sectional view taken along lined-4.

of Figure 3;

Figure '5 is an inverted perspective-view of a bow and stabilizer assembly shown inFigures'2,

3, and 4;

Figure 6 is a perspective view orithestabilizer forming a part of the mechanism shown inFig-j ures 2, '3, and 4;

Figure '7 is a view corresponding in part to Figure 3, but showing a different embodiment;

Figure 8 is a partial sectional view taken along lined-8 of Figure 7;

Figure 9 is a perspective view of the stabilizer employed in the embodiment of Figures 7 and 8';

F e 0 is a view corresponding to'Figure*3, but howing a further embodiment of the inven-- tion and Figure 11 is a sectional view taken alongline l i'i l of Figure 10.

are so stabilized with reference to each other,

and guided in their 'relative'tmovement, as to be noiseless and free of wear despite the constant.

reversal of direction during operation. The word noiseless is used herein in-the practical'jsensel as indicating that the noise resulting from normal operation is not perceptible to the unaided ear. By free of wear, as the expression is'herein used, is'meant thatthe parts are subject'toso little 'wearthat the useful life of other parts of the machine is exhausted before 'theme'chan'ism concerned.

Ihavediscovered that'noiseless operation and freedom from Wear in the oscillating'mechani'sm of a washing machine maybe accomplished with,

an Indian fire stick type of mechanism it means he provided'to assure that theline' of pull is at all times tangential to a circle offixediradius concentric with the agitator axis. The invention,

therefore, contemplates the-provision of stabilizing means whereby, irrespective of the direction of movement at .any increment of time, and irrespective of the position or the parts at any increment of time, the lineof .pull is tangential to the same circle (but not at the same-radius of -that' circle) Referring now to Figures lto 6, inclusive, for I an illustrative embodiment of the invention, the washing machine is provided with a source of motive power, such as an electric motor I connected by a belt 2 to a pulley 3, which latter drives the oscillating mechanism encased in a casing 4 and preferably running in lubricant. The casing 4 is mounted upon the frame of the machine below a tub 5, within which is contained the usual agitator or dolly 6. The agitator 6 oscillates on a vertical shaft 1, the latter being driven by the oscillating mechanism now to be described.

As shown clearly in Figures 2 and 3, the pulley 3 is secured to a shaft 8, which extends through appropriate bearings in casing 4, and on the interior of the casing is provided with a worm 9. The worm 9 meshes with a worm wheel I I) mounted for rotation upon a vertical shaft II. The worm wheel I is provided with a crank-pin I2 arranged to receive abow member I3. The bow member I3 provides spaced anchorages I4 and I5 for the connection of the free ends of two roller chains I6 and II, respectively.

On'the agitator shaft I, two sprockets I8 and I9, of a pitch and conformation to interfit with the chains I6 and II, respectively, are mounted in a manner such as to drive the agitator shaft 1. The end of chain I6 remote from. anchorage I4 is wrapped in one direction about sprocket I8 and secured thereto by a pin 20 extending through a lug 2I on the sprocket I8. Likewise, the end of chain I7 remote from anchorage I5 is wrapped in the opposite direction about sprocket I 9 and secured thereto by a pin 22 extending through a lug 23 on the sprocket I9. The pitch diameter of the sprockets I8 and I9 is so chosen that, at the extreme positions, one or more teeth of the sprockets, in addition to the lugs 2I and 23 thereof, as the case may be, are'engaged with rollers in the respective chains I6 and I1, so that at no time is the entire load sustained by the pin-andlug, connections above described.

The invention is particularly concerned with eliminating the tendency, during movement, for the bow I3 to assume positions of differing radial displacement from the center of shaft I. In order 'to maintain the radial displacement (by which is meant the radial distance between the bow and the center), a stabilizer 24 is mounted for pivotal movement concentric with'shaft I and arranged to slide in a slot 25 extending lengthwise of bow I3, as clearly shown in Figures 4 and 5. In the embodiment shown, the stabilizer' 24 is T'-shaped, having a mounting leg provided with an aperture 26 adapted to be received on shaft 7 and have a running fit therewith. At the opposite extremity, the stabilizer 24 is provided with a blade 21 having a thickness such asto be received in slot 25 of bow I3 and have a sliding fit therein. The length of the stabilizer 24, from the axis of hole 26 to blade 21, is carefully controlled so that, when blade 2'! is seated in slot 25 of bow I3, 2. straight line passing through the' pin centers of the straight portions of the chains I6 and II and the center of crank-pin I2 will be tangent to the pitch circle of sprockets I8 and I9; Some variation from tangence to the pitch circle may be tolerated provided, at all'times in its cycle of movement, the bow I3 is tangent to the same circle, i. e., maintained at fixed radial displacement from the center of shaft I. The interconnection provided between the bow I3 and shaft 1 by stabilizer 24 assures this.

' Inthe embodiment shown in the drawings,'the casing 4 and its companion lid 40 perform'the bolts, or otherwise, and such attachment mainfunction not only of encasing the parts and keeping them sealed in lubricant, but also of maintaining the several parts in assembled relation. The shaft I I is mounted in a boss M and secured against rotation therein by a nut 42. In accordance with a common practice, the shaft I I is provided with an eccentric portion 43 whereby the worm gear I Il may be adjusted into'proper relationship with the worm 9. The worm wheel III, however, rotates freely upon shaft II and is held in position thereon within the casing 4 by the arrangement of parts now to be described.

The crank-pin I2 is mounted in a hole of proper size in worm wheel ID as, for example, by pressfitting the parts together. Surrounding the crank-pin I2, the worm wheel is provided with a boss 44 constituting a seat against which the knuckle boss 45 of bow I3 may be pressed with a suitable washer 43 intervening, if desired. The outer end of crank-pin I2- is reduced in diameter, as shown at 41, forming a shoulder 48 on the crank-pin just inwardly of the outer extremity of boss 45 on the bow I3. A spring washer'49 is arranged upon the reduced portion 41 of crankpin I2 and surmounted by a fiber annulus 50,

which extends slightly beyond the outer extremity. of reduced portion 4'! on crank-pin I2. The fiber annulus 50 is proportioned in axial dimensions so that, when lid is applied to the casing 4, the

fiber annulus 58 will be pressed against the action of spring washer 49, thus pressing boss toward the worm wheel, and the worm wheel toward the opposite side of easing 4. The inner surface of lid 40 is provided with a raceway 5I annular in shape and substantially concentric with shaft II. The race-Way 5| has the surface thereof, which is exposed for contact with the fiber annulus 50,

finished in such manner as to have good sliding properties with reference to fiber annulus 50, which moves thereabout under the pressures of spring washer 49. If desired, the race-way 5I may be formed of different material from that of" lid 40 and suitably anchored thereto so as to provide a sliding path for the end of fiber annulus 50.

With the arrangement of parts just described, no nuts, pins, keys, or other fastenings are required to hold the bow I3 and the worm wheel II) in properly assembled relation within casing 4. The lid 40 is secured to the casing by suitable tains the aforesaid parts in their proper assembled relation. The pressure of spring 49 is exerted wholly between annulus 50 and boss 45. The

- reaction from the former is received by lid 40. 'while the reaction from the latter is received by the bottom of casing 4 through the intervention of washer 46 and worm wheel III.

A further embodiment is shown in Figures 7, 8, and 9 wherein, in lieu of the bow and stabilizer in the form above described, the stabilizer andbow are formed integrally, as shown in Figure 9. In this embodiment, the bow I30 has a boss I3I for connection'with crank-pin I2, and is provided with anchorages I34 and I35 for connecting the ends of chains I6 and I1.

The bow I3!) is provided with a flange I32 having an elongated slot I33, whose width is such as to be received over agitator shaft 1 and have a running fit therewith. The displacement between the center of slot I33 and the anchorages I34 and I35 is regulated so that, as in the pre-' vious embodiment, the straight portion of thechain is tangent at all times to'a circle of fixed radius concentric with shaft 1.

A further embodiment is shown in Figures and 11, in which, in contrast to the previous embodiments, the rectilinear portion of the drive chain is not fixedly stabilized so as to be tangent with the desired circle, but is resiliently so stabilized. In this embodiment, the shaft '1 is provided with a roller I01 freely running thereon. The outer periphery of the roller l0? engages a fiat I08 on bow H3. Thus the engagement between the roller I01 and bow H3 positively prevents movement of the bow H3 in a direction so as to reduce the radial displacement from the center of axis 1 below a predetermined value controlled by the radius of roller I01. In order to assure the maintenance of the proper radial displacement in this instance, however, a springbiased roller I 14 is provided for engagement with a flat I09 on the opposite side of bow H3 from roller I01. In the embodiment shown, the roller I I4 is mounted upon the free end of a cantilever spring H5. In this, as in the previous embodiments, the dimensions of the parts are so chosen that the rectilinear portion of the chains will at all increments of time during operation be tangent to a circle of given radius and be in straight-line relation with the axis of crankpin [2.

In the apparatus shown in Figures 1 to 9, inclusive, the oscillating mechanism operates emciently, noiselessly, and without wear in the practical sense.

While, in the embodiment shown in Figures 10 and 11, the radial displacement between the bow and the agitator shaft is not fixed, the tension exerted by the spring thereon may be sufficient to maintain this displacement sufficiently constant for practical purposes and, when the tension of the spring is sufiicient to maintain the constant displacement, the operation is almost as noiseless as with the other embodiments.

Utilizing the oscillating mechanism shown in Figures 1 to 6, inclusive, a test run of 1700 hours washing time was carried out with the machine under load. The power consumption utilizing the oscillating mechanism of the present invention was approximately seventy-five percent of the power consumption of the same machine equipped with conventional oscillating mechanism and, at the end of such run, the oscillating mechanism of the present invention was as noiseless as at the beginning and showed no perceptible signs of wear or looseness.

From the foregoing description those skilled in the art should readily understand that the present invention accomplishes its objects and provides an oscillating mechanism for washing machines, which is not only noiseless and free from wear, but cheap to manufacture and dependable in operation. While three complete embodiments of the invention have been disclosed in detail, it is not to be understood that the invention is limited to those embodiments but, on the contrary, that the principles thereof may be adapted and applied by numerous forms and arrangements of parts consistent with the principle that the bow be caused to travel at fixed radial displacement from the center of the oscillating shaft. Consistent with that principle, such modifications and variations as present themselves to those skilled in the art are contemplated by and within the scope of the appended claims.

Having thus described the invention, what is claimed and desired to be secured by Letters Patent is:

1. In an oscillating mechanism for a shaft comprising a rotatable crank, a bow connected to said crank for operation thereby, and tension members extending from said bow and wrapped about said shaft; the combination of spacing means cooperating with said how and said shaft for maintaining constant radial distance between said shaft and said bow.

2. The combination of claim 1 wherein the spacing means comprises a part mounted on said shaft for concentric rotation relative thereto, said part interengaging said bow and relatively slidable lengthwise thereof.

3. The combination of claim 1 wherein the spacing means comprises an extension on the bow having a slot extending in a direction lengthwise of the bow, said slot being received on said shaft and rotatable relative thereto.

The combination of claim 1 wherein the tension members are anchored to said bow in spaced relation lengthwise thereof and wherein the anchorages are aligned rectilinearly with the connection between said crank and said bow.

5. In an oscillating mechanism for the agitator shaft of a washing machine, a casing having separable sections, means for connecting the sections together, a shaft mounted in one of the sections, a crank mounted on said shaft and having an eccentric pin arranged to move about an orbit concentric with said shaft, a pitman journaled on said pin, a slide bearing on said pin outwardly of said pitman, overlapping the latter, and engaging the opposite one of said casing sections, and the last mentioned one of said casing sections having an annular slideway for said bearing conforming to the orbit of said pin.

6. The combination of claim 5 wherein the slide bearing is fiber and a spring washer is interposed between said pitman and the fiber bearmg.

7. In an oscillating mechanism for a shaft comprising, a rotatable crank, a bow connected to said crank for operation thereby and tension members anchored at spaced points to said bow, said tension members being wrapped about said shaft between said points of anchorage, the improvement which comprises, said points of anchorage being located on a straight line with the connection between said bow and said crank, and means for maintaining said straight line in tangent relation with and at a fixed radial distance from the center of said shaft.

OTTO J. VOSS.

References Cited in the file of this patent 

